Furnace



Dec. 4, 1928;

F. H. ROSENCRANTS FURNAC E Filed Nov. l5, 1925 vwemto'a ffm @Mom/Le d5 Patented Dec. v4, 19.28.

FURNACE.

'Application filed November 13, 1925. Serial No. 68,783.

This invention relates to furnaces and is particularly useful in connection with furnaces adapted to burn finely divided fuel 1n suspension, as for example, carburetted oil or pulverized coal and it has for one of its primary objects the provision of improvements with reference to the air supply for combustion to the end that efficiency may be improved and more perfect combustion obtained.

increase the boiler'output while still keeping*L 1 down the size of the installation.

- vertical compartments The foregoing, together with such other objects as may hereinafter appear, or are incident to my invention, are realized by a construction which I have illustrated in preferred form in the accompanying drawing, which is a. partial vertical section and side elevation of an oil fed stationary boiler installation embodying my improvements.'

Referring now to the drawing, the reference character A denotes the combustion chamber over which is located the boiler B, such boiler being bailled so asto provide three passes a, o, the lirstgof which constitutes the outlet for the products of combustion completed within the combustion chamberA.

In normal operation the flue gases pass through the dampers 11,thr011gh the breaching 10 and air pre-heater 12,- into the flue 8. A bypass 7 controlled bydampers 9 is also provided by Virtue of which the gases may be passed directfrom the boiler tothe main flue rather than through the air preheater. Th-e air preheater shown is preferably of multiplate type now wellunderstood in this art.

The side walls 13, the rear wall 14 and the bottom 15 of thel combustion chamber are hollow, air being taken in at the rear thru the inlet 16 from whence it passes downwardly thru the rear wall to the space beneath the floor. The lower portion of the space within the side walls is divided into tions 17, and the air iiows from the space below the door into these compartments rising upwardly thru the side walls and eventually entering the breaching 18; from this breaching the air enters the heater 12 and is (l by means of partidischarged into the combustion space thru the breaching 19. In the present instance an oil burner 20 is located so as to discharge into the lower portion of the combustion chamber and the air is discharged from the breaching 19 around this burner.

The circulation above described is brought about by the fan 2 The amount of gas passing over the air heater is determined by manipulation of the dampers 9 and 11 by virtue of which as much of the waste gases as desired are caused to pass thru the breaching 10 to the iue 8.

he air in' passing downward thru the rear wall, then beneath the ioor and then upwardly thru the side walls, absorbs heat and in so doingcontinues, to cool the refractories and extend their life.v The air thus preheated is further heated, preferably to a very high temperature, in the air heater 12 and asthus highly heated it is delivered around the burner and mixed with the entering fuel whereby ignition takes place romptly, combustion is completed within a s ort space of time with a high temperatured flame. In other words, I greatlyincrease the temperature head thereby increasing both boiler and` furnace etticiency and also'increasing the rate of heat absorptionby the boiler.

prefer to use a boiler of smaller size than customary so that the Waste gases entering the heater may be higher than usual. By d0- ing so. I am enabled to preheat the airto a lhigh degree with the final exit temperatures not unduly high. The increase in temperaturehead I thus obtain enables me to generate more steam-by virtue of the higher rate of absorption incident to the increase in furnace temperature.

It will be obvious that under these conditions the flame will be short and hot and thus both the furnace itself and the boiler may be of comparatively small size as compared with the standard installation intended t deliver the same amount of steam.

It is advantageous to have the side walls hollow all the way up.

What I claim is:

1. In combination, a boiler furnace having hollow rear, side and bottom walls, an ofltake, a waste gas air heater, an air inlet in an upper part of the back wall, and breaching communicating with the upper part of the side ,walls together with means wherebyr 'air for l through the rear wall into the bottom wal gas'oitake, a waste gas by-pass having an air Vheater located therein, and means whereby air through the rear wall, bottom wall, side walls and air heater.

4. In combination, a boiler furnace having hollow rear, side and bottom walls, a waste gas otake, a waste gas by-pass having an air heater located therein, and means whereby air for 4combustion is caused to pass serially through the rear wall, bottom wall, side walls and air heater, said otake and said by-pass being damper controlled.

- 5. In combination, a boiler furnace having hollow rear, side and bottom walls, a waste gas air heater, means for controlling the temperature thereof, and means whereby air for combustion is caused to pass serially through the rear wall, bottom wall, side walls and air heater. A

combustion is caused to pass downwardly 7 upwardly through the side walls and throu lr the air heater to the combustion space of t e furnace. 1

2. In combination, a boiler furnace having hollow rear, side and bottom walls, the space in the side walls being divided into a plurality of vertically disposed channels communieating at theirv lower ends with the space inthe bottom wall and at their upper. ends with a breaching, together with means for causing air for combustion to pass downwardly through said rear wall and into the bottom wall and thence upwardly through said channels and'into said breaching. y 3. In combination, a boiler furnace having hollow rear, side and bottom walls, a'waste signed my name.

FAY H. ROSENCRANTS.

for combustion is cans to pass serially In testimony whereof, I have hereunto 

